// SPDX-FileCopyrightText: 2023 The wlroots contributors
// SPDX-FileCopyrightText: 2023 KylinSoft Co., Ltd.
//
// SPDX-License-Identifier: GPL-1.0-or-later

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>

#include <wlr/types/wlr_output.h>
#include <wlr/types/wlr_output_layout.h>

#include "output_p.h"
#include "xdg-output-unstable-v1-protocol.h"
#include "xwayland.h"

#define OUTPUT_MANAGER_VERSION 3
#define OUTPUT_DONE_DEPRECATED_SINCE_VERSION 3
#define OUTPUT_DESCRIPTION_MUTABLE_SINCE_VERSION 3

struct xdg_output_v1 {
    struct wl_list resources;
    struct wl_list link;

    struct wlr_output_layout_output *layout_output;

    int32_t x, y;
    int32_t width, height;

    struct wl_listener destroy;
    struct wl_listener description;
};

struct xdg_output_manager_v1 {
    struct wl_global *global;
    struct wlr_output_layout *layout;

    struct wl_list outputs;

    struct {
        struct wl_signal destroy;
    } events;

    struct wl_listener display_destroy;
    struct wl_listener layout_add;
    struct wl_listener layout_change;
    struct wl_listener layout_destroy;
};

struct xdg_output_manager_v1 *manager = NULL;

static void output_handle_destroy(struct wl_client *client, struct wl_resource *resource)
{
    wl_resource_destroy(resource);
}

static const struct zxdg_output_v1_interface output_implementation = {
    .destroy = output_handle_destroy,
};

static void output_handle_resource_destroy(struct wl_resource *resource)
{
    wl_list_remove(wl_resource_get_link(resource));
}

static void output_send_details(struct xdg_output_v1 *xdg_output, struct wl_resource *resource)
{
    int32_t x = xdg_output->x, y = xdg_output->y;
    int32_t width = xdg_output->width, height = xdg_output->height;

    if (xwayland_check_client(wl_resource_get_client(resource))) {
        x = xwayland_scale(x);
        y = xwayland_scale(y);
        width = xwayland_scale(width);
        height = xwayland_scale(height);
    }

    zxdg_output_v1_send_logical_position(resource, x, y);
    zxdg_output_v1_send_logical_size(resource, width, height);
    if (wl_resource_get_version(resource) < OUTPUT_DONE_DEPRECATED_SINCE_VERSION) {
        zxdg_output_v1_send_done(resource);
    }
}

static void output_update(struct xdg_output_v1 *xdg_output)
{
    struct wlr_output_layout_output *layout_output = xdg_output->layout_output;
    bool updated = false;

    if (layout_output->x != xdg_output->x || layout_output->y != xdg_output->y) {
        xdg_output->x = layout_output->x;
        xdg_output->y = layout_output->y;
        updated = true;
    }

    int width, height;
    wlr_output_effective_resolution(layout_output->output, &width, &height);
    if (xdg_output->width != width || xdg_output->height != height) {
        xdg_output->width = width;
        xdg_output->height = height;
        updated = true;
    }

    if (updated) {
        struct wl_resource *resource;
        wl_resource_for_each(resource, &xdg_output->resources) {
            output_send_details(xdg_output, resource);
        }

        wlr_output_schedule_done(xdg_output->layout_output->output);
    }
}

static void output_destroy(struct xdg_output_v1 *output)
{
    struct wl_resource *resource, *tmp;
    wl_resource_for_each_safe(resource, tmp, &output->resources) {
        wl_list_remove(wl_resource_get_link(resource));
        wl_list_init(wl_resource_get_link(resource));
    }
    wl_list_remove(&output->destroy.link);
    wl_list_remove(&output->description.link);
    wl_list_remove(&output->link);
    free(output);
}

static void output_manager_handle_destroy(struct wl_client *client, struct wl_resource *resource)
{
    wl_resource_destroy(resource);
}

static const struct zxdg_output_manager_v1_interface output_manager_implementation;

static void output_manager_handle_get_xdg_output(struct wl_client *client,
                                                 struct wl_resource *resource, uint32_t id,
                                                 struct wl_resource *output_resource)
{
    assert(wl_resource_instance_of(resource, &zxdg_output_manager_v1_interface,
                                   &output_manager_implementation));

    struct wlr_output_layout *layout = manager->layout;
    struct wlr_output *output = wlr_output_from_resource(output_resource);

    struct wl_resource *xdg_output_resource = wl_resource_create(
        client, &zxdg_output_v1_interface, wl_resource_get_version(resource), id);
    if (!xdg_output_resource) {
        wl_client_post_no_memory(client);
        return;
    }
    wl_resource_set_implementation(xdg_output_resource, &output_implementation, NULL,
                                   output_handle_resource_destroy);

    if (output == NULL) {
        wl_list_init(wl_resource_get_link(xdg_output_resource));
        return;
    }

    struct wlr_output_layout_output *layout_output = wlr_output_layout_get(layout, output);
    assert(layout_output);

    struct xdg_output_v1 *_xdg_output, *xdg_output = NULL;
    wl_list_for_each(_xdg_output, &manager->outputs, link) {
        if (_xdg_output->layout_output == layout_output) {
            xdg_output = _xdg_output;
            break;
        }
    }
    assert(xdg_output);

    wl_list_insert(&xdg_output->resources, wl_resource_get_link(xdg_output_resource));

    // Name and description should only be sent once per output
    uint32_t xdg_version = wl_resource_get_version(xdg_output_resource);
    if (xdg_version >= ZXDG_OUTPUT_V1_NAME_SINCE_VERSION) {
        zxdg_output_v1_send_name(xdg_output_resource, output->name);
    }
    if (xdg_version >= ZXDG_OUTPUT_V1_DESCRIPTION_SINCE_VERSION && output->description != NULL) {
        zxdg_output_v1_send_description(xdg_output_resource, output->description);
    }

    output_send_details(xdg_output, xdg_output_resource);

    uint32_t wl_version = wl_resource_get_version(output_resource);
    if (wl_version >= WL_OUTPUT_DONE_SINCE_VERSION &&
        xdg_version >= OUTPUT_DONE_DEPRECATED_SINCE_VERSION) {
        wl_output_send_done(output_resource);
    }
}

static const struct zxdg_output_manager_v1_interface output_manager_implementation = {
    .destroy = output_manager_handle_destroy,
    .get_xdg_output = output_manager_handle_get_xdg_output,
};

static void output_manager_bind(struct wl_client *wl_client, void *data, uint32_t version,
                                uint32_t id)
{
    struct wlr_xdg_output_manager_v1 *manager = data;

    struct wl_resource *resource =
        wl_resource_create(wl_client, &zxdg_output_manager_v1_interface, version, id);
    if (resource == NULL) {
        wl_client_post_no_memory(wl_client);
        return;
    }
    wl_resource_set_implementation(resource, &output_manager_implementation, manager, NULL);
}

static void handle_output_destroy(struct wl_listener *listener, void *data)
{
    struct xdg_output_v1 *output = wl_container_of(listener, output, destroy);
    output_destroy(output);
}

static void handle_output_description(struct wl_listener *listener, void *data)
{
    struct xdg_output_v1 *xdg_output = wl_container_of(listener, xdg_output, description);
    struct wlr_output *output = xdg_output->layout_output->output;

    if (output->description == NULL) {
        return;
    }

    struct wl_resource *resource;
    wl_resource_for_each(resource, &xdg_output->resources) {
        if (wl_resource_get_version(resource) >= OUTPUT_DESCRIPTION_MUTABLE_SINCE_VERSION) {
            zxdg_output_v1_send_description(resource, output->description);
        }
    }
}

static void add_output(struct xdg_output_manager_v1 *manager,
                       struct wlr_output_layout_output *layout_output)
{
    struct xdg_output_v1 *output = calloc(1, sizeof(struct xdg_output_v1));
    if (output == NULL) {
        return;
    }
    wl_list_init(&output->resources);
    output->layout_output = layout_output;
    output->destroy.notify = handle_output_destroy;
    wl_signal_add(&layout_output->events.destroy, &output->destroy);
    output->description.notify = handle_output_description;
    wl_signal_add(&layout_output->output->events.description, &output->description);
    wl_list_insert(&manager->outputs, &output->link);
    output_update(output);
}

static void output_manager_send_details(struct xdg_output_manager_v1 *manager)
{
    struct xdg_output_v1 *output;
    wl_list_for_each(output, &manager->outputs, link) {
        output_update(output);
    }
}

static void handle_layout_add(struct wl_listener *listener, void *data)
{
    struct wlr_output_layout_output *layout_output = data;
    add_output(manager, layout_output);
}

static void handle_layout_change(struct wl_listener *listener, void *data)
{
    output_manager_send_details(manager);
}

static void manager_destroy(struct xdg_output_manager_v1 *manager)
{
    struct xdg_output_v1 *output, *tmp;
    wl_list_for_each_safe(output, tmp, &manager->outputs, link) {
        output_destroy(output);
    }
    wl_signal_emit_mutable(&manager->events.destroy, manager);
    wl_list_remove(&manager->display_destroy.link);
    wl_list_remove(&manager->layout_add.link);
    wl_list_remove(&manager->layout_change.link);
    wl_list_remove(&manager->layout_destroy.link);
    free(manager);
    manager = NULL;
}

static void handle_layout_destroy(struct wl_listener *listener, void *data)
{
    manager_destroy(manager);
}

static void handle_display_destroy(struct wl_listener *listener, void *data)
{
    manager_destroy(manager);
}

bool xdg_output_manager_v1_create(struct server *server)
{
    manager = calloc(1, sizeof(struct xdg_output_manager_v1));
    if (manager == NULL) {
        return false;
    }
    manager->layout = server->layout;
    manager->global = wl_global_create(server->display, &zxdg_output_manager_v1_interface,
                                       OUTPUT_MANAGER_VERSION, manager, output_manager_bind);
    if (!manager->global) {
        free(manager);
        manager = NULL;
        return false;
    }

    wl_list_init(&manager->outputs);
    struct wlr_output_layout_output *layout_output;
    wl_list_for_each(layout_output, &server->layout->outputs, link) {
        add_output(manager, layout_output);
    }

    wl_signal_init(&manager->events.destroy);

    manager->layout_add.notify = handle_layout_add;
    wl_signal_add(&server->layout->events.add, &manager->layout_add);
    manager->layout_change.notify = handle_layout_change;
    wl_signal_add(&server->layout->events.change, &manager->layout_change);
    manager->layout_destroy.notify = handle_layout_destroy;
    wl_signal_add(&server->layout->events.destroy, &manager->layout_destroy);

    manager->display_destroy.notify = handle_display_destroy;
    wl_display_add_destroy_listener(server->display, &manager->display_destroy);

    return true;
}

void xdg_output_update_scale(float scale)
{
    if (!manager) {
        return;
    }

    struct xdg_output_v1 *output;
    wl_list_for_each(output, &manager->outputs, link) {
        struct wl_resource *resource;
        wl_resource_for_each(resource, &output->resources) {
            /* found xwayland client */
            if (xwayland_check_client(wl_resource_get_client(resource))) {
                output_send_details(output, resource);
                break;
            }
        }
    }
}
